I don't know exactly what it is, but I've had a few brands over the years that include King, Selmer, Corton, Yanagisawa,Yamaha, Martin, Buescher Keilworth, Grassi.
If I can only have one horn it would have to be my Selmer to reduce the FOMO to its minimum. But I don't think FOMO is the right expression actually, perhaps I just mean the most satisfying singular choice for me.
You can look at a saxophone dispassionately as a necessary tool or you can throw many more things in to the equation.
As hobby players are likely romancing about their influences, so there should always be room for a Conn 10 (notably left out of this type of conversation regularly as people prefer to cite selmer as the dying enemy every single time) Old King, Buescher or Selmer etc. You'll never see Ben Webster playing a P Mauriat with a SYOS mouthpiece. Without suggesting that would be possible if he were around today, what he did back then still means something to people today.
A pro on tour has a different criteria and may be worried about what may happen to something more unique and of high value opting for something entirely different.
I can't say if a sax like 'Better sax', 'Bauhaus Walstien' or 'Jehrico' etc wouldn't be every bit as good to play or maintain as a long established top brand sax.
But I can say, something is missing in ownership experience for me.
I appreciate hand made element and craftsmanship, ornate features, classic designs while others wont care.
On new instruments the fake aging

and unlacquered look are simply out there to try to catch that side or the market. To me that is very misguided and in the case of unlacquered, has nothing to do with tone preference, others may love it and argue that point.
Endorsement is also another red herring regarding new horns.
I have enough experience to understand household name players can be seduced into endorsement and say all the right things about the brand but not all of them feel the same way in the longer term. Just watch YouTube and note the dates of performance and often you'll see them using something else later on. Another word on YouTube and all things web wide, remember you can say what you like and it can be viewed by as many or as few people as search for such.
Fan boys and haters.
I say play what pleases
you within your budget.
So if you are chucking out your Selmer I'll take it.